热防护系统热真空模拟试验技术

介绍了一种能模拟可重复使用运载器热防护系统内、外表面气动热和压力环境的热真空模拟试验装置,该装置不仅能模拟TPS外表面所受气动热和气动压力条件,还能模拟TPS内表面的真空压力环境。其外部环境压力4．0×10^2-2.0×10^5Pa,内部环境压力4．0～1．013×10^5Pa,热面温度可高达1100℃。利用该装置可以对热防护系统的传热性能进行稳态和瞬态测试。简要介绍了该装置的构成及功能,以及用其进行材料和结构的传热性能测试的试验方法。该装置的研制将为我国高超音速飞行器热防护系统的验证提供必要的技术手段。     

SiO2气凝胶砂浆性能的优化研究

目的研究Si O_2气凝胶颗粒体积替换比在30%前提下砂浆性能的优化,提高其保温性能和环境适应性。方法采用正交实验的方法,通过向砂浆中添加纤维、引气剂和胶粉来改善砂浆的保温性能,并对比研究各掺杂比例对砂浆密度、力学性能、吸水率,尤其是对砂浆导热系数的影响。结果当纤维、引气剂和胶粉的掺量(质量分数)分别为0.2%,0.05%和1%时,导热系数达到最低,λ=0.3177 W/(m·K),此时,砂浆的密度为1751.6 kg/m3,抗压强度和抗折强度分别为13.4 MPa和8.02MPa,吸水率为7.19%,导热系数为0.3177 W/(m·K)。结论通过添加纤维、引气剂和胶粉,砂浆的性能得到一定程度的改善,其密度在较小的范围内变化,抗折强度提高较大,导热系数在一定范围内降低。     

Characterization of bacterial community and iron corrosion in drinking water distribution systems with O3-biological activated carbon treatment

Bacterial community structure and iron corrosion were investigated for simulated drinking water distribution systems(DWDSs) composed of annular reactors incorporating three different treatments: ozone, biologically activated carbon and chlorination(O_3-BAC-Cl_2);ozone and chlorination(O3-Cl_2); or chlorination alone(Cl_2). The lowest corrosion rate and iron release, along with more Fe_3O_4 formation, occurred in DWDSs with O_3-BAC-Cl_2 compared to those without a BAC filter. It was verified that O_3-BAC influenced the bacterial community greatly to promote the relative advantage of nitrate-reducing bacteria(NRB)in DWDSs. Moreover, the advantaged NRB induced active Fe(III) reduction coupled to Fe(II) oxidation, enhancing Fe_3O_4 formation and inhibiting corrosion. In addition, O_3-BAC pretreatment could reduce high-molecular-weight fractions of dissolved organic carbon effectively to promote iron particle aggregation and inhibit further iron release. Our findings indicated that the O_3-BAC treatment, besides removing organic pollutants in water, was also a good approach for controlling cast iron corrosion and iron release in DWDSs.     

AP/HTPB底排推进剂降压熄火试样的热分解研究

为了掌握AP/HTPB底排推进剂降压熄火后的热分解特性,采用半密闭爆发器制备AP/HTPB底排推进剂降压熄火的试样,利用DSC方法进行微量样品在3种升温速率下的热分解试验,并与AP/HTPB原样测试结果进行对比分析.结果表明,在相同升温速率下,降压熄火后的AP/HTPB底排推进剂的DSC曲线中,放热峰的形状发生了变化,...     

油井酸化缓蚀剂述评

本文扼要介绍了国内外近年来在研究和应用油井酸化缓蚀剂方面的现状和发展，并列出了美国几家公司研制的缓蚀剂的性能试验数据。对目前我国的研究工作提出了看法和建议。     

耕作层下土地自然净化系统成本分析

对土地处理法中适合于小城镇的耕作层下土地自然净化系统的成本进行了分析研究。通过对已经运行的几个实际工程的建设投资与运行费用的数据监测与收集,利用SPSS17.0数据处理软件进行拟合,得到处理规模（Q,m3/天）与建设投资（C,万元）之间的关系C=258.130 6Q0.433 7。预测了不同处理规模该系统建设投资与运行...     

Internal corrosion hazard assessment of oil & gas pipelines using Bayesian belief network model

A substantial amount of oil & gas products are transported and distributed via pipelines, which can stretch for thousands of kilometers. In British Columbia (BC), Canada, alone there are over 40,000 km of pipelines currently being operated. Because of the adverse environmental impact, public outrage and significant financial losses, the integrity of the pipelines is essential. More than 37 pipe failures per year occur in BC causing liquid spills and gas releases, damaging both property and environment. BC oil & gas commission (BCOGS) has indicated metal loss due to internal corrosion as one of the primary causes of these failures. Therefore, it is of a paramount importance to timely identify pipelines subjected to severe internal corrosion in order to improve corrosion mitigation and pipeline maintenance strategies, thus minimizing the likelihood of failure. To accomplish this task, this paper presents a Bayesian belief network (BBN)-based probabilistic internal corrosion hazard assessment approach for oil & gas pipelines. A cause-effect BBN model has been developed by considering various information, such as analytical corrosion models, expert knowledge and published literature. Multiple corrosion models and failure pressure models have been incorporated into a single flexible network to estimate corrosion defects and associated probability of failure (PoF). This paper also explores the influence of fluid composition and operating conditions on the corrosion rate and PoF. To demonstrate the application of the BBN model, a case study of the Northeastern BC oil & gas pipeline infrastructure is presented. Based on the pipeline's mechanical characteristics and operating conditions, spatial and probabilistic distributions of corrosion defect and PoF have been obtained and visualized with the aid of the Geographic Information System (GIS). The developed BBN model can identify vulnerable pipeline sections and rank them accordingly to enhance the informed decision-making process.     

锅炉运行中的腐蚀原因分析及处理对策

就锅炉水侧金属壁上产生锈泡的主要原因进行了分析,并提出了相应的处理对策及煮锅的操作过程和方法。     

高盐量循环水的缓蚀试验研究

矿井酸性水中和后循环应用的主要问题是高盐量造成的腐蚀问题。通过对高盐量循环水的腐蚀试验,得出腐蚀速度CR与总盐量、时间的相互关系,通过对缓蚀剂的筛选试验,得出SEH+SPZ缓蚀配方,并确定其应用条件。该研究为缺水的盐碱地区矿业用水提供了有益的途径和借鉴。     

我国多功能水处理剂的研究现状

综述了我国多功能水处理剂的现状，通过分析相关资料，说明了多功能水处理剂的研究重点及方向是进一步提高产品的质量、开发新品种。